Facilitating Ulvan Extraction from Ulva lactuca via Deep Eutectic Solvent and Peracetic Acid Treatment

Abstract

Ulva lactuca is a green seaweed and commonly referred to as sea lettuce and contains sulphated polysaccharides that have biological activity. Strong acids (HCl) and strong bases (NaOH) are commonly used as solvents in the conventional extraction process for ulvan, despite its lack of ecological sustainability. Deep Eutectic Solvent (DES) is an alternative to ulvan extraction solvent which is more environmentally friendly and has low toxicity. Ulvan extraction using DES with a temperature of 85-95ºC for 1 hour, and adding 2% peracetic acid pretreatment, 0.1%, 0.5%, and 2% peracetic acid posttreatment were conducted. Peracetic acid pre- and post-treatment (PAA) was carried out with a 1:10 (w/v) ratio at room temperature for 30 minutes. This study aims to optimize the use of DES in ulvan extraction with pre- and post-treatment of ulvan quality. The analysis performed included moisture content, yield, functional groups, sulphate content, and color. The test results revealed that ulvan treated with 2% PAA pretreatment had the highest moisture content and sulphate content, at 18.71% and 33.39%, respectively, while ulvan treated with 0.1% PAA posttreatment had the highest yield, at 41.96%. The addition of peracetic acid concentration can increase the color quality of the ulvan. PAA pre- and post-treatment had a significant effect on all ulvan quality parameters.